I love the ER-X because it's cheap, generally available and a fine router with SQM. Just keep in mind that with smart queue enabled it will top out at about 150-170Mbit. If you're on a faster connection the Edgerouter ER4 with its faster quad core CPU should be able to handle up to about 300-350Mbit.

When you need to shape even more bandwidth, routers based on the Marvel XP Armada chipset do very well. I flashed a Linksys WRT1900ACS with OpenWRT and was able to shape about 600-750Mbps before it ran out of horsepower.